1. Field of the Invention
The present invention relates to a developing device for use in image forming apparatus such as copying machines, printers and the like, and more specifically relates to a seal member and a supporting portion of a regulating member in a developing device.
2. Description of the Related Art
FIGS. 1 through 4 show the construction of conventional developing devices. In this developing device 50, the housing 51 is provided with a roller accommodating compartment 52 disposed opposite a photosensitive member (not illustrated), and a toner supply compartment 53 disposed posteriorlyto said compartment 52. The roller accommodating compartment 52 and the toner supply compartment 53 are interconnected via a transverse inlet 54.
The developing roller 55 is arranged in the roller accommodating compartment 52, such that both ends of the support shaft (not illustrated) are inserted in receptacles 56 provided on the side panels of the housing 51 so as to be freely rotatable while supported.
The regulating panel 57 is arranged behind the developing roller 55, the top portion of said regulating panel 57 is fixedly mounted to the front wall 58 of the toner supply compartment 53, the bottom free end of said panel 57 is in pressure contact with the exterior surface of the developing roller 55.
The elastic seal member 62 comprises four members 63, 66, 66, and 67, i.e., bottom seal member 63 provided with a side seal member 65 at bilateral ends of the bottom seal 64, side seal members 66 and 66, and top seal member 67. The elastic seal member 62 forms a seal between the roller accommodating compartment 52 and toner supply compartment 53, when the bottom seal 64 is interposed medially to the bottom of the housing 51 and the bottom exterior surface of the developing roller 55, the side seals 65 and 65 and the side seal members 66 and 66 are interposed medially to the side walls of the housing 51 and both end surfaces of the developing roller 55, and the top seal member 67 is interposed medially to the regulating member 57 and the housing 51.
The seal member 68 comprises a body 69 arranged in the axial direction of the developing roller 55, and side seals 70 and 70 extending from bilateral ends of said body 69 along the exterior surface of the developing roller 55. The end portions of the body 69 are fixedly attached to the bottom of the housing 51, the body 69 is interposed medially to the bottom seal 64 and the developing roller 55, and the side seals 70 and 70 are interposed medially to the side seals 65 and 65, side seal members 66 and 66 and the developing roller 55. The ends of the side seals 70 and 70 are stretched under tension in the arrow direction via a force imparting means not shown in the drawings.
Since the aforesaid elastic seal member 62 comprises the aforesaid tightened four members 63, 66, 66 and 67, when the developing device 50 is arranged horizontally, the toner may leak from the seams of the seal members 63, 66, 66 and 67 into the roller accommodating compartment 52, which has the disadvantage of dispersing toner within the apparatus.
The regulating panel 57 makes direct contact with the housing 51, and is covered by metal panels 59 and 60 which act as reinforcing members that are fixedly attached thereto by a plurality of screws 61. As shown in FIG. 3, the regulating panel 57 partially mounted by screws 61 is thereby fixedly attached to the housing 51. Although a suitable quantity of toner is maintained on the developing roller 55 in the aforesaid portion, in the areas between the screws 61 the metal panels 59 and 60 are lifted via the return force of the regulating panel 57 as shown in FIG. 4, such that the regulating panel 57 exerts a weak pressure on the developing sleeve 55, and toner in excess of the standard quantity is maintained on the developing roller 55 passing this portion, thereby causing spotting of the image density.